1. Field of the Invention
This invention relates to a decoupler for exhaust pipe of automobiles, and more particularly, to the decoupler for effectively absorbing the pitching vibration and rolling motion due to the vertical connection of the exhaust pipes, thereby improving durability of the exhaust system and passengers"" comfort.
2. Description of the Prior Art
Generally, engines of the vehicle are connected to the exhaust pipe employing a muffler for exhausting the exhaust gas from the vehicle. For connection, a decoupler is installed to absorb and buffer the vibration displacement, impact load or heat deformation.
The decoupler on this location should absorb vibrations and displacement occurring depending on the movement of the exhaust system due to the engine and road vibrations. It may involve the excessive displacement occurring in any directions such as tension compression, bending, deflection and so on.
In order to maintain airtight of the exhaust gas and improve absorbing capability of the vibration displacement, the bellows is usually fabricated from metal.
A number of attempts have been made in the prior art to design an effective decoupler. One attempt to solve the problems of the prior art is demonstrated by Korean UM application 2000-2443 in which the decoupler functionally absorbs the displacement in the bending direction.
In the prior art (FIG. 5), an inner sleeve 20xe2x80x2 in a cylindrical shape is fixed inward the bellows 10xe2x80x2 which maintains the exhaust gas to be airtight and absorbs the expansion and bending displacement, so as to protect the bellows and guide the exhaust gas of high temperature to pass through.
A guide member 40xe2x80x2 is located at the one end of the bellows 10xe2x80x2 for having a circular-arc surfaces 41xe2x80x2 and 42xe2x80x2 with respect to the motion center Cxe2x80x2 of the bellows 10xe2x80x2 to surround the bellows 10xe2x80x2.
At the other end of the bellows 10xe2x80x2, a cover member 50xe2x80x2 is located outward the guide member 40xe2x80x2 for having an inclined section 51xe2x80x2 at a predetermined angle with respect to the motion center Cxe2x80x2 in the frontward and a buffering protector 54xe2x80x2 integrally bent in the rearward.
First and second mesh rings 60xe2x80x2 and 61xe2x80x2 are located between the respective ends of the cover member 50xe2x80x2 and the circular-arc surfaces 41xe2x80x2 and 42xe2x80x2 of the guide member 40xe2x80x2 respectively, wherein inner surfaces being in a contact with the circular-arc surfaces 41xe2x80x2 and 42xe2x80x2 and outer surfaces being fixed at the inclined section 51xe2x80x2 and the buffering protector 54xe2x80x2.
In case that a displacement occurs in the bending direction during travelling of the vehicles, the circular-arc surfaces 41xe2x80x2 and 42xe2x80x2 of the guide member 40xe2x80x2 is slid along the contact surface of the first and second mesh rings 60xe2x80x2 and 61xe2x80x2, thereby absorbing the impact displacement.
However, Korean UM application 2000-002443 is not configured to absorb tension or compression displacement and pitching vibration, but the impact due to the bending displacement.
FIG. 1 (Prior Art) shows that when the conventional decoupler is vertically mounted in the exhaust pipes, it cannot absorb the pitching vibration, thereby reducing the durability and vibration absorbing or noise reduction capabilities.
It has another disadvantage that the scope to be applied of the decoupler is very limited.
Accordingly, it is an object of the present invention to provide a decoupler with cushion mesh rings in which the pitching vibration from the engine is effectively absorbed even in a vertical connection to the exhaust pipes, to improve the durability of the exhaust system and passengers"" comfort.
The another object of the present invention is to provide a decoupler for absorbing various vibration displacements from the engine, thereby increasing the scope to be applied.
According to an aspect of the present invention, a decoupler includes a bellows made of metal and formed in cylindrical and a repeatedly corrugated shapes for absorbing bending and expansion, the bellows being airtight with respect to exhaust gases therein. The decoupler further includes an inner, cylindrical sleeve disposed in the bellows for protecting the bellows from the exhaust gas passing through the cylindrical sleeve. A guide member is disposed at the one end of the bellows and includes a cylindrical portion having circular-arc surfaces at its opposite ends and is disposed outside of and around at least a portion of the bellows. A cover member is disposed at the other end of the bellows and includes a body portion having first and second inclined sections at its opposing ends, the inclined sections being inclined relative to the body portion, the cover member being disposed outside of and around at least a portion of the bellows. A first mesh ring and a second mesh ring are disposed between the guide member and the cover member and form a sliding surface in contact with the body portion of the cover member and the circular-arc surfaces of the guide member. A first cushion mesh ring and a second cushion mesh ring are disposed between the first inclined section of the cover member and the first mesh ring and the second inclined section of the cover member and the second mesh ring, respectively, the first cushion mesh ring and the second cushion mesh ring being made of a material that is adapted to be compressed and expanded.